Race condition: insertSessionDoc in internal_transactions_sharded_from_mongod.js asserts that the insert succeeds, but internal_transactions_sharded_from_mongod_kill_sessions.js which inherits this method kills the session before the replication completes.

internal_transactions_sharded_from_mongod_kill_sessions.js should catch the writeConcernError and ignore it, as it does with Interrupted error.